Prior art barrel locks and keys are shown in U.S. Pat. Nos. 1,923,025; 3,002,368; 3,835,674; and 4,040,279. The disclosures of these patents are incorporated herein by reference and made a part of the present disclosure. These prior art locks and keys have become increasingly less secure with the passage of time because of the relatively wide, albeit substantially controlled, distribution and use of the keys by a large number of people. Assignee's copending U.S. Pat. No. 4,441,343, the disclosure of which is incorporated herein by reference, described one approach to overcoming this problem.
It is the object of this invention to provide a barrel lock which cannot be opened with a conventional key or with picks or nails.